Fabric Shrinkage

Fabric shrinkage is a common concern for many people, especially when it comes to cherished garments. Understanding the science behind shrinkage is crucial for proper garment care and resizing. Fabric shrinkage is a natural phenomenon. It occurs due to various factors such as fiber type, fabric construction, and finishing processes. It can significantly impact the fit, appearance, and longevity of garments.

To assess the potential shrinkage of a fabric, fabric shrinkage tests are performed. These tests help manufacturers, designers, and consumers understand how much a piece of fabric or garment will shrink under specific conditions.

Understanding fabric shrinkage and conducting shrinkage tests are crucial steps in ensuring the quality and durability of fabrics. In this article, we will provide you with a complete guide to fabric shrinkage tests, including the importance of these tests, the testing process, and how to interpret the results.

Fabric Shrinkage Test – Definition

The amount of shrinkage depends on the fabric’s fiber content, weave, finishing, and the conditions to which it is exposed. The process to measure the change in dimension of fabric is called the Fabric Shrinkage Test. Moreover, this test also covers the change in the quality of the fabric.

Fabric shrinkage is the reduction in the size or dimensions of a fabric or garment after being exposed to heat or undergoing washing. Shrinkage can occur in both lengthwise (warp) and widthwise (weft) directions.

Reasons for fabric shrinkage

Fabric shrinkage can occur due to several reasons. Understanding these factors is essential to minimize shrinkage and maintain the quality of fabrics. Here are some common reasons for fabric shrinkage:

Fiber Type

Different fiber types have varying tendencies to shrink. Natural fibers like cotton and wool have a higher propensity to shrink compared to synthetic fibers such as polyester or nylon.

Fabric Construction

The construction of the fabric, including its weave or knit structure, can affect shrinkage. Fabrics with looser weaves or knits tend to have a higher chance of shrinkage than tightly woven or knitted fabrics.

Finishing Processes

Chemical treatments and finishes applied to fabrics during manufacturing can affect shrinkage. Some finishes, such as pre-shrinking treatments, are designed to minimize further shrinkage after washing. However, if these finishes are not applied or if the fabric is not properly treated, it may be more prone to shrinkage.

Heat and Moisture

Exposure to heat and moisture can trigger fabric shrinkage. Washing fabrics in hot water or drying them at high temperatures can cause the fibers to contract and lead to shrinkage. Similarly, excessive moisture or humidity can contribute to shrinkage too, especially in natural fibers.

Mechanical Agitation

Aggressive mechanical processes during washing or drying, such as high-speed spinning or tumble drying, can cause fabrics to shrink. The repeated friction and movement of the fabric can lead to dimensional changes.

Improper Care

Failure to follow proper care instructions can increase the risk of fabric shrinkage. Ignoring recommended washing temperatures, using harsh detergents, or subjecting delicate fabrics to rough handling can result in shrinkage.

Fabric Blends

Fabrics made from blends of different fibers may exhibit uneven shrinkage. If the fibers in the blend have different shrinkage properties, the fabric may experience distortion or uneven contraction during laundering.

Shrinkage rates of different fabrics

Different fabrics have varying rates of shrinkage due to their unique fiber compositions. Here are some general guidelines on the shrinkage rates of common fabric types:

Cotton

Cotton fabrics are known for their tendency to shrink. On average, cotton can shrink between 3% to 5% during the first wash and subsequent laundering. However, certain cotton fabrics, such as those labeled as “pre-shrunk” or subjected to pre-shrinking treatments during manufacturing, may have reduced shrinkage rates.

Wool

Wool is another natural fiber prone to shrinkage. It can shrink significantly, from 10% to 20%, especially if exposed to high temperatures or agitation during washing. To prevent excessive shrinkage, wool garments should be handled with care and washed using gentle methods.

Linen

Linen fabric is derived from flax fibers and has moderate shrinkage rates. On average, linen can shrink around 2% to 5% during the first wash. Subsequent laundering may cause minimal additional shrinkage.

Silk

Silk fabrics generally have low shrinkage rates compared to other natural fibers. They tend to shrink around 1% to 3% during washing. However, some silk blends or specialized silk weaves may exhibit slightly higher shrinkage rates.

Polyester

Polyester is a synthetic fiber known for its resistance to shrinkage. It has minimal shrinkage rates, usually less than 1%. This quality makes polyester fabrics popular for items where shape retention is essential, such as activewear and outdoor clothing.

Nylon

Nylon is another synthetic fiber with excellent dimensional stability. Like polyester, nylon fabrics have minimal shrinkage rates, typically less than 1%. They retain their shape well even after repeated laundering.

Blended Fabrics

Fabrics made from blends of different fibers can exhibit varying shrinkage rates depending on the composition. The shrinkage behavior of a blended fabric is influenced by the individual fibers it contains.

Factors Affecting Shrinkage

Several factors influence fabric shrinkage:

Fiber Type

Different fiber types exhibit varying levels of shrinkage. Natural fibers like cotton and wool tend to shrink more than synthetic fibers such as polyester.

Fabric Construction

The way a fabric is woven or knitted affects its shrinkage behavior. Tighter weaves generally experience less shrinkage compared to loose or open weaves.

Finishing Processes

Chemical treatments and finishes applied to fabrics during manufacturing can impact their shrinkage characteristics. Pre-shrinking treatments may reduce further shrinkage after the fabric is washed.

Fabric Shrinkage Test

Fabric shrinkage tests are conducted to measure and assess the dimensional changes that occur in fabrics after washing, drying, or exposure to heat. These tests help understand the potential shrinkage of fabrics and make informed decisions in fabric selection, sizing, and care.

There are specific testing standards and methods that are commonly followed in fabric shrinkage testing:

Testing Standards

Fabric shrinkage tests are typically performed according to recognized industry standards. Some commonly used standards for fabric shrinkage testing include:

• ASTM D3774: Standard Test Method for Width of Textile Fabric
• ASTM D4970: Standard Test Method for Pilling Resistance and Other Related Surface Changes of Textile Fabrics
• ISO 6330: Textiles – Domestic washing and drying procedures for textile testing
• AATCC TM135: Dimensional Changes in Automatic Home Laundering of Woven and Knit Fabrics

Testing Methods

In fabric shrinkage testing, two common testing methods are the impregnation method and the mechanical treatment method. These methods are used to assess the dimensional changes and shrinkage of fabrics. Let’s explore each method in detail:

Impregnation Method

The impregnation method involves immersing fabric samples in a liquid solution before subjecting them to testing conditions. The impregnation solution typically consists of water and any additional chemicals or detergents as specified by the testing standard or procedure.

Mechanical Treatment Method

The mechanical treatment method involves subjecting fabric samples to mechanical stress or agitation to assess their shrinkage behavior. This method aims to replicate the effects of mechanical actions during washing or drying.

The mechanical treatment method allows for the assessment of fabric shrinkage resulting from mechanical forces, providing insights into the fabric’s response to agitation and friction.

How Are These Methods Performed?

Impregnation Method

Here’s how the impregnation method is typically performed:

Sample Preparation: Fabric samples of standardized dimensions are cut from the test specimen. The samples are usually large enough to allow for the measurement of dimensional changes accurately.

Impregnation: The fabric samples are immersed in the impregnation solution, ensuring that all parts of the samples are thoroughly soaked. The impregnation solution may simulate a specific washing or laundering condition, such as a temperature-controlled water bath.

Resting Period: After impregnation, the fabric samples are allowed to rest for a specified period, usually to mimic the absorption and penetration of water during a typical washing cycle.

Mechanical Treatment: Following the resting period, the fabric samples may undergo additional mechanical treatment, such as agitation or squeezing, to simulate the effects of washing or rinsing.

Dimensional Measurement: The fabric samples are carefully removed from the impregnation solution and dried according to the testing standard or procedure. Once dry, the dimensional changes in the fabric samples are measured using calibrated instruments, and the shrinkage percentage is calculated based on the initial and final dimensions.

Mechanical Treatment Method

Here’s a typical procedure for the mechanical treatment method:

Sample Preparation: Fabric samples are prepared with standardized dimensions and marked for reference.

Mechanical Treatment: The fabric samples are placed in a mechanical device that can mimic the desired mechanical actions, such as a tumbling device or a mechanical agitator. The samples are subjected to repeated movements, rotations, and friction, simulating the forces experienced during washing or drying.

Dimensional Measurement: After the mechanical treatment, the fabric samples are carefully removed from the device, and their dimensional changes are measured using calibrated instruments. The initial and final dimensions are compared to calculate the shrinkage percentage.

Test apparatus

TESTEX Automatic Shrinkage Washer

Also known as the Shrinkage Washing Machine TF176, is a fully automatic shrinkage tester used for evaluating the dimensional stability of fabrics, clothing, and other textiles after washing. It adheres to standards such as GB/T 8629, ISO 5077, GB/T 8630, and ISO 6330. The machine has a rated loading capacity of 5+/-0.05kg and features touchscreen control.

It finds applications in textile enterprises, quality supervision agencies, commercial inspection agencies, and scientific research institutions for performing shrinkage and relaxation tests on various textiles like cotton, animal fur, silk, linen, and chemical fibers.

Features

The Automatic Shrinkage Washer comes with a range of notable features:

Flexible Programs: This machine has 16 sets of standard washing programs and 8 user-editable wash programs, providing a wide range of options for different testing requirements.

Professional Customization and Durability: The whole system of this machine is carefully customized, and developed by qualified engineers, and washing machine designers. This ensures a 100% durable design, and highly qualified material that can easily survive the toughest conditions.

Water Level and Spin Factor: It has high-quality sensors or rods that make sure that the water level and the speed of spinning do not cross their limits. It has the best conversion motors, to control everything.

No Vibration: This machine is connected to a box and a damper with the best quality. This is to make sure that the machine does not shake or vibrate during the power-up. You will not need anything to hold the machine firmly.

Corrosion-Resistant and High-Grade Construction: The inner cylinder and outer cylinder of the machine is made of stainless steel. This is to make sure that it stays neat and clean.

How To Use It?

Preparation: Start by gathering the fabric samples or garments you want to test for shrinkage. Ensure they are clean and free from any other substances.

Set up the machine: Connect the TESTEX Automatic Shrinkage Washer to a power source and ensure it is properly grounded. Fill the machine with the appropriate amount of water as per the manufacturer’s instructions. Add any necessary detergents or chemicals according to the testing requirements.

Load the samples: Open the door or lid of the machine and carefully load the fabric samples or garments into the drum. Make sure not to overload the machine, as it can affect the accuracy of the results. Close the door or lid securely.

Select the program: The TESTEX Automatic Shrinkage Washer typically comes with different preset programs or cycles for various testing purposes. Choose the appropriate program that matches your testing requirements. Refer to the machine’s user manual for specific details on program selection.

Adjust settings: Depending on the specific model, you may have additional settings to customize the testing parameters, such as water temperature, wash time, and agitation speed. Set these parameters accordingly, following the instructions provided by the manufacturer or as specified in the testing standards.

Start the cycle: Once you have selected the program and adjusted the settings, start the washing cycle by pressing the appropriate button or activating the start function. The machine will begin to fill with water and initiate the washing process.

Monitor the process: During the cycle, you can observe the machine’s operation to ensure everything is functioning correctly. Pay attention to any specific instructions or requirements for the test you are conducting.

Completion and results: Once the washing cycle is complete, the machine may automatically drain the water or require manual intervention. Open the door or lid and carefully remove the fabric samples or garments. Let them dry.

Method of Calculating Shrinkage

Calculating fabric shrinkage involves measuring the dimensional changes of the fabric before and after the testing process, using a Scale. The shrinkage percentage is determined by comparing the initial dimensions of the fabric to its final dimensions. Here is the method for calculating shrinkage:

Initial Measurement: Measure the dimensions of the fabric sample before subjecting it to any testing or treatment using a Shrinkage Template Scale. This includes measuring the length, width, and any other relevant dimensions. Record these initial measurements.

Testing Process: Carry out the specific testing process according to the chosen method. Ensure that the fabric sample is subjected to the required conditions, such as immersion in an impregnation solution or mechanical agitation. Follow the testing procedure accurately.

Final Measurement: Once the testing process is complete, carefully remove the fabric sample from the testing apparatus. Allow it to dry or undergo any required post-treatment, according to the testing standard or procedure. Once dry, measure the dimensions of the fabric sample again, using the Shrinkage Template Scale.

Calculation: With the initial and final measurements in hand, calculate the fabric shrinkage percentage using the following formula:

Shrinkage Percentage = [(Initial Dimension – Final Dimension) / Initial Dimension] x 100

For example, if the initial length of the fabric sample was 100 cm and the final length after testing was 90 cm, the calculation would be:

Shrinkage Percentage = [(100 – 90) / 100] x 100 = 10%

The resulting value represents the percentage of shrinkage that occurred in the fabric sample during the testing process.

If you want an instrument that automatically calculates the shrinkage rate of fabrics, our newest Smartshrink Rate Tester will be a good choice for you.

Shrinkage Template Scalenbsp;

The Shrinkage Template Scale TF178 is a measuring tool designed to measure the shrinkage rate of any fabric. It provides precise measurements that help in assessing the dimensional changes that occur during the drying. The scale is widely recognized in industries where shrinkage analysis plays a vital role, such as manufacturing, construction, and research.

Features

Enhanced Accuracy: The Shrinkage Template ruler offers exceptional accuracy, ensuring precise measurements of shrinkage. This accuracy allows businesses to make informed decisions based on reliable data, leading to improved product quality and customer satisfaction.

Improved Efficiency: By providing quick and accurate measurements, the scale streamlines the shrinkage analysis process. This improved efficiency saves valuable time and resources, allowing businesses to optimize their production cycles and meet project deadlines more effectively.

Consistency in Results: Consistency is crucial in industries that rely on shrinkage analysis. The scale provides consistent and repeatable results, minimizing variations and ensuring reliable data for comparison and analysis.

How to Use the Shrinkage Template Scale

Using the scale is straightforward and requires following a few simple steps:

• Prepare the shrinkage template by creating a mold or using a pre-existing one.

• Ensure the template has clearly defined initial dimensions.

• Place the template on a flat surface.

• Carefully position the scale next to the template.

• Use the scale measurement features to assess the dimensions before and after shrinkage.

• Record the measurements and calculate the shrinkage rate using the formula provided in the scale’s manual.

Tips and Best Practices

To achieve optimal results when using the scale, consider the following tips:

• Clean the scale regularly to prevent debris from affecting measurements.

• Follow the manufacturer’s instructions for calibration and maintenance.

• Take multiple measurements for increased accuracy.

• Store the scale in a dry and secure place when not in use.

• Consider wearing appropriate personal protective equipment (PPE) when working with certain materials.

Fabric Shrinkage Prevention Tips

Read and Follow Care Labels

Always read and follow the care labels attached to your fabrics and garments. Care labels provide specific instructions on how to handle and clean the fabric to minimize shrinkage. Pay attention to recommended washing temperatures, drying methods, and any special instructions.

Wash in Cold Water

To prevent fabric shrinkage, opt for washing your fabrics in cold water rather than hot or warm water. Cold water is less likely to cause fibers to contract and shrink. It helps to preserve the fabric’s integrity and keeps it from undergoing excessive changes in size.

Avoid High Heat

High heat, whether in the washing machine or dryer, can accelerate fabric shrinkage. Whenever possible, avoid using high heat settings. Instead, opt for low to medium heat settings to reduce the risk of shrinkage. High heat can cause the fibers to contract and alter the fabric’s dimensions.

Use Gentle Cycle and Mild Detergent

When machine-washing fabrics are prone to shrinkage, select the gentle cycle option on your washing machine. The gentle cycle reduces the agitation and friction that can lead to shrinkage. Additionally, choose a mild detergent specifically formulated for delicate fabrics to prevent harsh chemical reactions that may contribute to shrinkage.

Air Dry or Use Low Heat

After washing, consider air-drying your fabrics instead of using a dryer. Hang them on a clothesline or lay them flat on a clean, dry surface. If using a dryer, opt for the lowest heat setting or a delicate cycle. High heat can cause rapid shrinkage, so it’s best to minimize exposure to heat.

Fabric shrinkage can significantly affect the fit and quality of garments. Conducting fabric shrinkage tests is crucial for manufacturers, designers, and consumers to understand the potential changes in size after washing or heat exposure.

By following the outlined testing process and considering the various factors that influence shrinkage, you can make informed decisions regarding fabric selection, sizing, and garment care.

Can fabric shrinkage be reversed?

No, fabric shrinkage is usually permanent and irreversible. Once the fabric has shrunk, it is challenging to regain its original size.

Are all fabrics prone to shrinkage?

Not all fabrics shrink to the same extent. Natural fibers like cotton and wool tend to shrink more than synthetic fibers.

Can fabric shrinkage be prevented?

While fabric shrinkage cannot be entirely prevented, following proper care instructions and pre-shrinking techniques can minimize potential shrinkage.

How much shrinkage is considered acceptable?

Acceptable shrinkage levels vary depending on the fabric type and its intended use. Industry guidelines or project requirements usually provide acceptable shrinkage standards.

Can fabric shrinkage occur in both lengthwise and widthwise directions?

Yes, fabric shrinkage can occur in both lengthwise (warp) and widthwise (weft) directions, although the amount of shrinkage may differ.